Beverage container closures

ABSTRACT

A container for a carbonated beverage has an interrupted external screw thread surrounding its mouth opening engageable with an internal screw thread of a rotatable closure. The rotatable closure is in two parts and has a stiffened top member and a separate, rotatable depending rim to rotatably engage on the container and hold the top member in sealing engagement with the opening of the container. To prevent missiling on opening, pressure venting means such as slots extending through the closure may be provided. Alternatively, the rotatable closure may be configured to have a two stage opening movement. As the rotatable closure is made in two parts it has a low opening torque.

[0001] The present invention relates to the use of a rotatable closureto close a container for carbonated beverages, to a container forcarbonated beverages, and to a rotatable closure for a carbonatedbeverage container.

[0002] British patent No. 2,254,594 discloses a container for beer andother beverages which is particularly suitable for dispensing carbonatedbeverages to a large number of people at a public venue. The containerdisclosed in the identified British patent is made of plastics materialand has an unrestricted mouth opening such that the container itself canbe used as the drinking vessel. The opening has an external screw threadproximate thereto and the proposal of British patent No. 2,254,594 is toprovide a correspondingly threaded end closure.

[0003] There are currently large numbers of designs of closures forcontainers, including many designs of closures arranged to be affixedand removed from the corresponding container by a screw action. However,none of the readily available closures behave entirely satisfactorilywith a container of the type disclosed in the above identified Britishpatent.

[0004] The present invention seeks to provide closures which can be usedsatisfactorily with carbonated beverage containers.

[0005] According to a first aspect of the present invention, there isprovided the use of a rotatable closure to close a container forcarbonated beverages, wherein said rotatable closure comprises a topmember and a separate rim, the rim being held on the top member andbeing rotatable relative to the top member, and wherein said containerhas a body member having an opening at one end thereof, and externalengagement means formed on said body member proximate to said opening,wherein cooperable engagement means are formed internally of the rim ofsaid rotatable closure, and wherein the container opening is closed byengaging the engagement means of said rim with the engagement means ofthe container.

[0006] The use of a rotatable closure of an embodiment of the invention,which has a separate, rotatable, rim ensures that the container can bereliably closed against the pressure of its contents, and yet be openedrelatively easily. In this respect, to open the container it is onlynecessary to rotate the rim and not the top member of the closure. Ifthe container has a wide mouth opening, the top member forms a largepart of the closure. By this means, the opening torque of the closure isreduced quite considerably.

[0007] The container may be fabricated from any suitable material, forexample, from metal or glass. In a preferred embodiment, the containeris fabricated from plastics material.

[0008] Preferably, said opening defines an unrestricted mouth openingfor the container. For example, the opening may have a diameterexceeding 30 mm, or 50 mm.

[0009] In an embodiment, said cooperable engagement means on said rimand on the container are arranged such that said rotatable closure isengageable and removable from the container by rotating the rim of therotatable closure relative to the opening of the container.

[0010] As explained, the rotatable closure is removable from thecontainer by rotation of the rim, and preferably, rotation of said rimthrough less than one complete revolution thereof is effective to enableremoval of the closure.

[0011] In one embodiment, the cooperable engagement means comprises anexternal screw thread provided on said container around said opening.The screw thread on the container may be continuous or interrupted. Thescrew thread on the container may vary in pitch.

[0012] The cooperable engagement means on the interior of the rim of theclosure, for cooperation with the screw thread, for example, on thecontainer, may comprise a plurality of lugs and/or an internal screwthread.

[0013] In a preferred embodiment, a plurality of lugs are spaced aroundthe opening of the container, and an internal screw thread is providedon the interior of the rim of the closure for cooperation with saidlugs.

[0014] Preferably, to prevent missiling of the closure on opening,pressure venting means are associated with the closure. For example,said pressure venting means may comprise one or more slots extendingthrough said closure, and/or through said container.

[0015] Additionally and/or alternatively, said pressure venting meanscomprise means associated with said cooperable engagement means forimparting a two stage opening movement to said rotatable closurerelative to the opening of the container.

[0016] The present invention also extends to a container for carbonatedbeverages comprising a body member having an opening at one end thereof,and external engagement means formed on said body member proximate tosaid opening, and a rotatable closure engaged on said container to closethe opening, the rotatable closure comprising a top member and adepending rim, and wherein cooperable engagement means are formedinternally of the rim of said rotatable closure and engage the externalengagement means to hold the rotatable closure on the container.

[0017] As previously, the body member may be of any suitable material,for example of glass or metal. However, for use at public venues it ispreferred that the body member be fabricated of plastics material.

[0018] The rotatable closure defined above, and the rotatable closureincorporated in an embodiment of a container of the invention, may befabricated, at least in part, of metal. Closures incorporating metalgenerally have a lower coefficient of friction than closures madeentirely of plastics material and the use, therefore, of metal reducesthe opening torque.

[0019] The rim of the rotatable closure may be made of any suitablematerial, for example, of plastics or of metal.

[0020] The top member of the rotatable closure is preferably suitablyshaped to provide stiffness thereto.

[0021] In a preferred embodiment, the top member of the rotatableclosure is deformed inwardly. This deformation provides the closure witha large surface area and thereby stiffens the closure and enables it towithstand the pressure of the carbonated contents of the container.

[0022] In a preferred embodiment, the inward deformation of the topmember is utilised to form a seal between the closure and the container.

[0023] Preferably, the engagement between the rotatable closure and thecontainer is arranged such that the closure may be removed by rotatingit through less than one complete revolution thereof. This ensures quickand easy removal of the closure, a feature which is very important ifthe container is being used to dispense beverages at a public venue.

[0024] The container is also, preferably, provided with pressure ventingmeans to prevent missiling of the closure. Preferably, the pressureventing means are associated with the closure. For example, slots mayextend through the closure and/or the container. In one embodiment,these slots are adjacent to the engagement means of the closure.

[0025] Additionally and/or alternatively, means may be associated withthe engagement means of the closure to impart a two stage openingmovement thereto. For example, such means may be arranged to halt anopening movement of the closure relative to the container opening. Forexample, appropriate stops may be provided on the closure and/or on thecontainer. As the closure is rotated to effect opening, part of theclosure or of the container will abut against the stops. This arrest ofthe opening movement is designed to provide for pressure venting. Theeffect of the stops can be overcome by, for example, pressing down onthe closure whereby the rest of the opening rotation is enabled.

[0026] In an embodiment, cooperable engagement means on said rim and onthe container are arranged such that said rotatable closure isengageable and removable from the container by rotating the rotatableclosure relative to the opening of the container. For example, saidrotatable closure may be removable by rotating said closure relative tothe periphery of the opening, and wherein rotation of said closurethrough less than one complete revolution thereof is effective to enableits removal.

[0027] Preferably, the cooperable engagement means comprises an externalscrew thread provided on said container around said opening. The screwthread on the container may be continuous or interrupted.

[0028] The cooperable engagement means on the interior of the rim of theclosure, for cooperation with the screw thread, for example, on thecontainer, may comprise a plurality of lugs and/or an internal screwthread.

[0029] In an alternative embodiment, the cooperable engagement meanscomprise an internal screw thread on the rim of said rotatable closure.

[0030] Said screw thread on the rim may be interrupted, and/or may varyin pitch.

[0031] In this embodiment, said cooperable engagement means furthercomprise a plurality of lugs provided on said container and spacedaround said opening, said lugs being engageable with said internal screwthread.

[0032] The container as defined above may have any of the features ofthe use of the rotatable closure as defined above, and/or any of thefeatures of the rotatable closure as defined below.

[0033] Similarly, the use of the rotatable closure as defined above mayincorporate any of the features of the container as defined above,and/or any of the features of the rotatable closure as defined below.

[0034] The present invention also extends to a rotatable closure for acarbonated beverage container, said rotatable closure comprising a topmember, and a peripheral rim depending relative to said top member, andwherein the top member is shaped to stiffen the closure.

[0035] In an embodiment, said peripheral rim is separate from the topmember and is held on the top member to be rotatable around theperiphery thereof.

[0036] The rotatable closure may be fabricated and configured as definedabove.

[0037] Embodiments of the present invention will hereinafter bedescribed, by way of example, with reference to the accompanyingdrawings, in which:

[0038]FIG. 1 shows schematically a carbonated beverage container with aclosure therefor,

[0039]FIGS. 2a, 2 b, and 2 c show respectively the mouth opening of acontainer having engagement means in the form of a series of lugs, anextended view of the mouth opening, and an extended view of the internalsurface of a closure cooperable therewith,

[0040]FIGS. 3a and 3 b show schematically part of a thread provided on arotatable closure and the lugs on the container mouth opening, andillustrate the closing and opening movements of the closure,

[0041]FIG. 4 shows a section through an embodiment of a rotatableclosure, for use with a carbonated beverage container,

[0042]FIG. 5 shows a further rotatable closure of the type shown in FIG.4,

[0043]FIG. 6 shows a still further embodiment of a rotatable closure ofthe type shown in FIG. 4, and

[0044]FIG. 7 shows an alternative embodiment of a rotatable closure ofthe type shown in FIG. 4,

[0045]FIG. 8 shows an embodiment of a rotatable closure of the presentinvention, wherein part of the rotatable closure is illustrated inposition on the annular periphery of a mouth opening of the container.

[0046]FIG. 9 shows an interior plan view of a top member of the closureof FIG. 8, and

[0047]FIG. 10 shows an alternative embodiment of the closure and openingconfiguration as shown in FIG. 8.

[0048] The invention is described herein specifically with reference toa carbonated beverage container of plastics material as described, forexample, in UK patent No. 2,254,594. However, whilst the presentinvention has been specifically designed for use with such a container,the invention is not limited to containers as described and claimed inthe British patent. For example, a carbonated beverage container of theinvention may be made of a plastics material, or of glass, or of metal,or of any other suitable material.

[0049]FIG. 1 shows an example of a beverage container of plasticsmaterial for use for dispensing beer or other carbonated beverages. Inthis respect, the container comprises of substantially cylindrical bodymember 2 of plastics material having a closed end 4 and a generallycircular mouth opening 6 at the end thereof opposed to said closed end4. An interrupted external screw thread 8 is provided on the body member2 and surrounds, but is spaced from, the mouth opening 6.

[0050] The container of FIG. 1 is also provided with a closure 100having an internal screw thread (not visible) arranged to engage thescrew thread 8 of the container. Thus, when the body member 2 has beenfilled, the closure 100 can be engaged thereon by engaging the screwthreads of the closure and of the body member and then rotating orscrewing the closure to its closed position. When it is required to haveaccess to the contents of the container, the closure 100 is removed andmay be discarded.

[0051] The construction and configuration of the closure 100, and themethod of its engagement on the container, has to be chosen with care tomeet a number of desired criteria. It is, of course, required that theclosure 100 is able to withstand the pressure of the contents of thecontainer when the container has been filled with a carbonated beverage.However, it is also generally required that the closure can be removedquickly. Where the closure is engaged by rotation or by screw action,the requirement for easy and speedy access generally means that theclosure should not have to be rotated more than one complete revolutionin order to release it. However, in general, the smaller the amount ofrevolution required to remove the closure, the greater the danger thatthe closure will be missiled off due to the pressure of the containercontents.

[0052] Similarly, it is required that there be a seal between theclosure and the container when the container is closed in order to keepthe beverage pressurised. However, the greater and more effective theseal, the greater the risk that the required opening torque will beunacceptably large.

[0053]FIG. 4 illustrates an embodiment of a two-part rotatable closure100 for use with a container as indicated in FIG. 1. The closure 100comprises a top member 102, for example, made of a metal, which isgenerally in the form of a circular disc but has an annular channel 104provided therein. Furthermore, the top member 102 is also formed to havea radially extending flange 106. The top member 102 carries a dependingperipheral rim 108 which has two axially spaced, radially extendingflanges 110 and 112 engageable with the flange 106 of the top member tohold the rim 108 relative to the top member 102. On the internal annularsurface of the rim 108, engagement means, such as a screw thread 120,are provided. The rim 108 is held on the top member 102 to be freelyrotatable relative thereto.

[0054] The engagement means may comprise a plurality of lugs arranged toengage with the screw thread 8 on the body member 2 of the container.Where the screw thread 8 is interrupted, for example as shown in FIG. 1,the lugs on the closure may be spaced apart by a distance substantiallythe same as the length of each length of the screw thread 8. With thisarrangement, the rotatable closure 100 of FIG. 4 may be engaged with thebody member by a screw action which is effective to position each lugbeneath a length of the screw thread 8. Removal of the closure 100 iseffected by a reverse screw action.

[0055] The top member 102 of the closure is shaped to provide stiffnessto the construction and, therefore, to provide the ability for theclosure 100 to withstand the pressure within the beverage container. Inthis respect, the top member 102 may have any suitable shape whichimparts the necessary stiffness. For example, a double curve may beimposed on the top member and/or a star shape may be impressed therein.Frequently, shapes in which the top member 102 is inwardly deformed willbe used as such shapes facilitate the incorporation of sealing means asdescribed further below.

[0056] The embodiments described so far show the use of an interruptedscrew thread on the body member 2 of the container for engagement with ascrew thread or with lugs provided on an inner surface of a rim of theclosure. However, it will be appreciated, that any cooperable engagementmeans, which enable the closure to be reliably engaged on the container,and enable removal of the closure by a twisting action may be utilised.For example, threads may be provided on the body member or on theclosure and such threads may be continuous or interrupted. The other ofthe closure and the body member may be provided with cooperatingthreads, with lugs, recesses, guides, or other formations.

[0057] However, there is an advantage to utilising a screw thread on oneof the container and the closure, and lugs on the other of the closureor container, as such an arrangement enables pressure venting for theclosure to be provided.

[0058] In this respect, FIG. 2a shows part of the body member 2 of a iscontainer having a plurality of lugs 30 provided externally of the bodymember 2 and around the mouth opening 6. FIG. 2b shows an extended viewof the neck showing the lugs 30, whereas FIG. 2c shows an extended viewof the inner cooperating surface of a depending peripheral rim of aclosure, as 100, which is provided with an interrupted screw thread 40.This closure 100 is to be used with the body member 2 of FIG. 2a.

[0059]FIGS. 3a and 3 b show adjacent sections or lengths of theinterrupted screw thread 40 provided on the inner surface of the rim ofthe closure 100. As can be seen, the lengths of the screw thread 40 areshaped to guide the lugs 30 during opening and closing, and at one end,each length of the screw thread 40 has an angle flat section 42 and atits other end, each length of screw thread 40 has a further flat 44terminated in a stop 46. A lug 30 of the body member 2 of the containerwill lie on a respective angle flat 42 in the closed condition of theclosure.

[0060] When the closure 100 is to be opened, its depending peripheralrim 108 is rotated relative to the mouth opening 6 whereby each lug 30is moved along the corresponding length of the screw thread 40 until thelug 30 is received in the position 30′. In that position, the stop 46prevents further relative rotation between the closure rim and thecontainer. However, if the closure is then pressed downwardly, the lug30 is positioned above the stop 46, and further rotation of the closurerim, and hence removal of the closure, can be achieved. This two stageopening of the closure allows pressure to be vented whilst the closureand the container are still engaged. Thus, the stops 46 are effective asanti-missiling stops.

[0061] It will be appreciated that in the arrangement shown in FIGS. 3aand 3 b, the lengths of screw thread 40 are shaped to have a variablepitch. By this means, the removal of the closure from the body memberemploys a camming action derived from the variation in pitch. Of course,alternative constructions can be provided.

[0062] The particular screw thread and lug configuration illustrated isarranged to enable removal of the closure upon rotation thereof throughless than one complete revolution. Preferably, removal is arranged tooccur after about one quarter of one revolution of the closure.

[0063] As is illustrated in FIG. 4, when the closure 100 is in positionclosing a container, the periphery of the container's mouth opening, as6, is received within the annular channel 104 as earlier described. Inthis respect, and as indicated in FIG. 4, a sealing compound 122 may bereceived within the channel 104. The sealing of the container in theclosed position of the closure 100 can thereby be ensured.

[0064] Alternative sealing means, such as a rubber ring (not shown), maybe housed within the channel 104.

[0065] To open a container closed by the closure 100, the rim 108 isgrasped, in normal manner, and is rotated relative to the container.However, whereas with a conventional one part closure the whole of theclosure has to be rotated, opening of the container utilising a closureas 100 can be achieved by rotation of the rim 108 only whereby theopening torque is considerably reduced.

[0066] The closure 100 shown in FIG. 4 may additionally and/oralternatively be provided with pressure venting means, for example, inthe form of slots (not shown) extending through the rim 108 from itsinner to its outer surface. Such slots, for example, may extend upwardlyfrom an opening in the inner surface of the rim 108 and exit in theflange 110. When the rim 108 is rotated to open the container, theaction of the screw thread 120 on the corresponding thread or lugs ofthe container lifts the closure and may be sufficient to partially orfully break any seal between the closure and the container. This enablespressure from the interior of the container to be vented by way of thevent slots in the closure. Continued rotation of the rim 108 theneffects removal of the closure 100.

[0067] Of course, the pressure venting slots may be incorporated in anysuitable area of the closure and/or container. For example, pressureventing slots may extend through the screw thread 120 of the closure,and/or through the corresponding screw thread or other engagement meansof the container.

[0068] The rim 108 of the closure may be made of any suitable material.For example, the rim 108 may be made of a plastics material.Alternatively, the rim 108 may be made of metal, for example, it may bea spun or pressed metal threaded band.

[0069]FIG. 5 shows schematically an alternative embodiment of theclosure 100 in which the top member 102 is inwardly deformed. In theembodiment shown in FIG. 5, the top member 102 is inwardly indented.FIG. 6 shows an alternative embodiment in which the top member 102 isinwardly domed. In both of the embodiments of FIGS. 5 and 6, the inwarddeformation of the top member 102 increases the surface area of the topmember and hence increases the stiffness of the closure and its abilityto withstand pressure as described earlier.

[0070]FIG. 7 shows a still further embodiment of the closure 100 inwhich the radially extending flange 110 of the rim 108 extends over thetop member 102. In the embodiment illustrated in FIG. 7, the peripheryof the mouth opening of a container 160 is shown received within theannular channel 104 of the closure 100.

[0071]FIGS. 8 and 9 show an embodiment of a rotatable closure 200 of thepresent invention. Specifically, FIG. 8 shows part only of the closure200 engaging on the annular periphery of the mouth opening 6 of acontainer as 2 to close the mouth opening.

[0072] As previously, the rotatable closure 200 is a two-part closurehaving a top member 202 from which a depending peripheral rim 208extends. The closure 200 shown in FIG. 8 acts as a bore and top sealwhich is dynamically sealed in and on the mouth opening 6.

[0073] In the embodiment shown in FIG. 8, the engagement means on theexterior of the annular periphery of the mouth opening 6 are not shown.However, it will be appreciated that such engagement means are providedand are arranged to be engaged by screw threads 220 provided on thedepending rim 208.

[0074] The top member 202 of the closure 200 comprises, as can be seenin FIG. 9, a substantially circular, planar, disc 212 with a flat outersurface and a plurality of stiffening ribs 210 on its internal surface.The top member 202 has a radially extending, circumferential portion 213extending around the outer circumference thereof. A first, inner annularrim 214 and a second, outer annular rim 216 each depend downwardly fromsaid circumferential portion 213. In the embodiment illustrated, thereare six radially extending internal ribs 210 which extend from thecentre of the disc 212 to the downwardly depending inner rim 214. Itwill be seen that the two rims 214 and 216 together define a downwardlyopen annular channel 224 which extends annularly around thecircumferential portion 213 of the top member 202.

[0075] The top member 202 may be made of a plastics material or of ametal. Where it is formed of a plastics material it may be a coextrusionor co-injection of foil and polypropylene or other plastics material. Itis possible, for example, to mix the plastics material with an oxygenscavenger before moulding the disc 212.

[0076] As the top, external surface of the central disc 212 issubstantially planar, instructions for use and/or advertising materialmay be affixed to the external surface of the top member 202.

[0077] Preferably, the external diameter of the inner rim 214 of the topmember 202 is the same as, or slightly larger than, the internaldiameter of the mouth opening 6 of the container. This means that thetop member 202 has to be forced into position during closure of thecontainer whereby a very good and efficient seal is produced within themouth opening 6.

[0078] As described previously, a sealing member, such as a gasket (notshown), may be provided in the channel 224 in the top member 202.Additionally and/or alternatively, sealing compound, such as compound122, may be provided in the channel 224. In the embodiment shown in FIG.8, the top of the mouth opening 6 of the container is provided with aprojection 260. This projection is made stiff so that it can deform thesurface of the channel 224 with which it comes into contact. In thisway, further enhanced sealing of the closure on the mouth opening 6 canbe achieved.

[0079] As previously, the rim 208 of the closure is engaged on anddepends from the top member 202 and is rotatably engaged by way of screwthreads 220 on screw threads (not shown in FIG. 8) on the outerperiphery of the mouth opening 6.

[0080] It will be seen from FIG. 8 that the rim 208 has a radiallyextending flange 230 which, in the closed position of the closure 200,engages on the top, external surface of the radially extendingcircumferential portion 213 of the top member 202. Thus, when theseparate rim 208 of the closure is engaged on the mouth opening 6 toclose the container, the rim 208 holds the channel 224 of the top member202 in position on the mouth opening 6 to make and retain a pressurewithstanding seal therebetween. Where the contents of the container arecarbonated, the pressure of the contents will tend to push the innerdepending rim 214 of the top member 202 against the mouth opening 6whereby a further pressure seal is made and retained. The strengtheningribs 210 on the top member 202 prevent bowing of the disc 212 outwardlyby the pressure of the contents.

[0081] Where the contents of the container are beer, for example, it isgenerally preferred to fill the container at a temperature of 3° C. orlower to maintain its carbonation during filling. However, the containerhas to be capable of withstanding the pressure of its contents andmaintaining the seal of its closure at temperatures up to 40° C. In apreferred embodiment, at least the material of the separate rim 208 ofthe closure 200 and of the body of the container defining the mouthopening 6 is the same so that the two elements react similarly as thecontainer is subjected to differing temperatures. Preferably, both thecontainer body and at least the separate rim 208 of the closure are ofan appropriate plastics material.

[0082] It will be appreciated that the container and its closure 200, asillustrated in FIGS. 8 and 9, provide sealing against the pressure ofthe container contents both within the inner diameter, or bore, of themouth opening 6 and at the top surface of the mouth opening. This topand bore seal is, because of the construction of the closure 200,dynamically reactive to the pressure of the contents. Nevertheless,because only the separate rim 208 of the closure has to be rotated torelease the closure, opening of the container by removal of the closure200 is relatively simple. Once the rim 208 is rotated in an openingdirection, the top seal begins to be released whereby the bore seal cansimilarly be released. In general, the construction of the closure andthe sequential release of the seals thereof enable gas to be vented fromthe container so that there is no danger of missiling of the closure.However, pressure venting means to further allow venting on opening andthereby prevent missiling may also be provided.

[0083]FIG. 10 show an alternative embodiment, similar to that of FIG. 8,but with an annular projection 270 formed on an interior surface of theseparate rim 208. When the closure 200 is in its closed position, theouter depending rim 216 of the top member 202 is pinched between theseparate rim 208 and the mouth opening 6 of the container to assist insealing the container. The pinching action is able to maintain the sealeven where there are different amounts of creep or contraction in theplastics material of the container and the closure.

[0084] It will be appreciated that variations to and modifications inthe embodiments as described and illustrated may be made within thescope of the invention as defined in the appended claims.

1. The combination of a container for a carbonated beverage and arotatable closure for the container, the container comprising a bodymember having an opening at one end thereof, said opening having anannular periphery and defining an unrestricted mouth opening for thecontainer, the rotatable closure comprising a top member having aperiphery and a separate depending rim, the rim being engageable withthe periphery of the top member and being rotatable relative to the topmember, and the combination further comprising first external engagementmeans formed on said body member proximate to said opening and secondengagement means formed internally of the rim of said rotatable closure,said first and second engagement means being engageable to allow saidrotatable closure to be engaged on and removed from the container byrotating the rim of the rotatable closure relative to the opening of thecontainer, wherein the rotatable closure is selectively rotatable to aclosed position that closes and seals said opening and being arranged,in said closed position, to withstand a pressure of and substantiallymaintain a pressurized state of the contents of the container when thecontainer has been filled with a carbonated beverage, wherein the topmember of the rotatable closure comprises a substantially circular paneland a radially extending, circumferential portion extending around theouter circumference of said circular panel, and a first, inner annularrim, and a second, outer annular rim, each said rim depending downwardlyfrom said circumferential portion, said inner and outer rims beingspaced to define therebetween a downwardly open annular channelextending around the circumferential portion of the top member, whereinthe annular periphery of the container opening is received within saidannular channel in the closed position of the rotatable closure toprovide a seal at the top of the container opening, and, in the closedposition of the rotatable closure, the inner rim of the top member isengaged against an interior surface of the annular periphery of thecontainer opening to provide a seal within the container opening, andwherein the circular panel of the top member is stiffened to withstandthe pressure of the contents of the container.
 2. A combinationaccording to claim 1, wherein the circular panel is siffened by aplurality of stiffening ribs formed on an interior surface of thecircular panel.
 3. A combination according to claim 1, wherein theannular periphery of the container opening is provided with an annularprojection for receipt within, and engagement with, the annular channelof the top member in the closed position of the rotatable closure.
 4. Acombination according to claim 1, wherein an internal surface of theseparate depending rim carries an annular projection arranged to engagethe second, outer annular rim of the top member in the closed positionof the rotatable closure.
 5. A combination according to claim 1, whereinthe material of the body member of the container and the material of theseparate depending rim of the rotatable closure are the same.
 6. Acombination according to claim 1, further comprising pressure ventingmeans defined by at least one of said container and said rotatableclosure for allowing pressure to be vented from the interior of thecontainer upon rotation of the rim of said rotatable closure out of theclosed position during opening of the container.
 7. A combinationaccording to claim 6, wherein said pressure venting means comprise oneor more slots extending through said rotatable closure.
 8. A combinationaccording to claim 6, wherein said pressure venting means comprise oneor more slots extending through said container.
 9. A combinationaccording to claim 6, wherein said pressure venting means comprise meansassociated with said first and second engagement means for imparting atwo stage opening movement of said rotatable closure relative to theopening of the container.
 10. A combination according to claim 1,wherein said unrestricted mouth opening for the container has a diameterwhich exceeds 30 millimeters.
 11. A combination according to claim 10,wherein said unrestricted mouth opening has a diameter exceeding 50millimeters.
 12. A combination according to claim 1, wherein the topmember of said rotatable closure is made of metal.
 13. A combinationaccording to claim 1, wherein the top member of said rotatable closureis made of plastics material.
 14. A combination according to claim 13,wherein an oxygen scavenger has been combined with said plasticsmaterial.
 15. A combination according to claim 1, wherein the separatedepending rim of the rotatable closure is made of a plastics material.16. A combination according to claim 15, wherein the body member of thecontainer is made of a plastics material which is the same as theplastics material of the separate depending rim.
 17. A combinationaccording to claim 1, wherein said rotatable closure is removable fromthe container by rotating the rim of the rotatable closure relative tothe opening of the container, and wherein rotation of said closurethrough less than one complete revolution thereof is effective to enableits removal.
 18. A combination according to claim 1, wherein said firstand second engagement means comprise lugs and/or stops provided on oneof the rim and of the container, and corresponding recesses, guidesand/or stops provided on the other of the container and of the rim. 19.A combination according to claim 1, wherein said first engagement meanscomprises an external screw thread provided on said container aroundsaid opening.
 20. A combination according to claim 19, wherein saidexternal screw thread on the container is interrupted.
 21. A combinationaccording to claim 19 or claim 20, wherein said second engagement meansfurther comprises a plurality of lugs on the interior of the rim of saidrotatable closure for engagement with said external screw thread.
 22. Acombination according to claim 19 or claim 20, wherein said secondengagement means comprises an internal screw thread on the rim of saidrotatable closure for engagement with said external screw thread.
 23. Acombination according to claim 1, wherein said second engagement meanscomprise an internal screw thread on the rim of said rotatable closure.24. A combination according to claim 23, wherein said internal screwthread is interrupted.
 25. A combination according to claim 23 or claim24, wherein said screw thread varies in pitch.
 26. A container accordingto claim 23, wherein said first engagement means comprise a plurality oflugs provided on said container and spaced around said opening, saidlugs being engageable with said internal screw thread.
 27. A combinationaccording to claim 6, wherein said second engagement means are formed onan inner surface of said rim of the rotatable closure, and said pressureventing means are associated with said second engagement means.
 28. Acombination according to claim 6, wherein said pressure venting meanscomprise one or more slots extending in said rim of the rotatableclosure.
 29. A combination according to claim 27 or claim 28, whereinsaid pressure venting means comprise means associated with said secondengagement means and arranged to cause said rotatable closure to requirea two stage opening movement.
 30. A combination according to claim 27and claim 28, wherein said pressure venting means comprise one or moreanti-missiling stops associated with said second engagement means. 31.The combination of a container for a carbonated beverage and a rotatableclosure for the container, the container comprising a body memberfabricated from plastics material and having an opening at one endthereof, said opening having an annular periphery and defining anunrestricted mouth opening for the container, the rotatable closurecomprising a top member having a periphery and a separate depending rim,the rim being engageable with the periphery of the top member and beingrotatable relative to the top member, and the combination furthercomprising first external engagement means formed on said body memberproximate to said opening and second engagement means formed internallyof the rim of said rotatable closure, said first and second engagementmeans being engageable to allow said rotatable closure to be engaged onand removed from the container by rotating the rim of the rotatableclosure relative to the opening of the container, wherein the rotatableclosure is selectively rotatable to a closed position that closes andseals said opening and being arranged, in said closed postion, towithstand a pressure of and substantially maintain a pressurized stateof the contents of the container when the container has been filled withcarbonated beverage, wherein the top member of the rotatable closurecomprises a substantially circular panel and a radially extending,circumferential portion extending around the outer circumference of saidcircular panel, and a first, inner annular rim, and a second, outerannular rim, each said rim depending downwardly from saidcircumferential portion, said inner and outer rims being spaced todefine therebetween a downwardly open annular channel extending aroundthe circumferential portion of the top member, wherein the annularperiphery of the container opening is received within said annularchannel in the closed position of the rotatable closure to provide aseal at the top of the container opening, and, in the closed position ofthe rotatable closure, the inner rim of the top member is engagedagainst an interior surface of the annular periphery of the containeropening to provide a seal within the container opening, and whereinpressure venting means are defined by at least one of said container andsaid rotatable closure, for allowing pressure to be vented from theinterior of the container upon rotation of said rim of said rotatableclosure out of said closed position during opening of the container.